FIG. 1 illustrates a power amplifier device as is known in the art. The prior art power amplifier device includes a power divider 101 to receive an input signal, a plurality of data flow paths, and a power combiner 116 to provide an output signal.
One data flow path illustrated in FIG. 1 comprises input impedance matching structure 104, amplifying device 108, and output impedance matching structure 112. The amplifying device 109 is typically a transistor device that amplifies a received signal. Data flows through conductive elements 102, 106, 110, and 114 to create a data flow path from the power divider 101 to the power combiner 116.
Another data flow path, analogous to the first data path, includes input impedance matching structure 105, amplifying device 109, and output impedance matching structure 113. Data flows through conductive elements 103, 107, 111, and 115 connect the various data flow elements to create a second data flow path from the power divider 101 to the power combiner 116. While only two data flow paths are indicated in FIG. 1, it will be appreciated that other power amplifiers can contain additional data flow paths, or only one data flow path.
The output impedance matching structures 112 in combination with the conductive elements 110 are implemented to realize an output load line structure to allow for partial impedance matching between the amplifying device 108 and the signal out node.
The structure illustrated in FIG. 1 has an inherent disadvantage in that there is a strong intra-dependence between the fundamental and harmonic frequency terminations exhibited by this circuitry. This strong intra-dependence limits the ability to select design parameters which can simultaneously optimize both the fundamental frequencies, and the harmonic frequencies. The inability to optimize both fundamental and harmonic frequencies prevents class F operation, or near class-F operation, of the device. Therefore, a device and/or method overcoming this problem would be advantageous.
The present disclosure relates generally to power amplifiers, and more particularly to power amplifiers having load line structures with harmonic frequency termination structures.